Особисті дані приховані

Denys
Serniuk
iOs developer
CONTACT ME WORK EXPERIENCE __________

MDA oct 2025
Senior iOs developer

iPhone storage cleaner
GITHUB Cleanup Pro is a high-performance, iOS application focused on large-scale
storage optimization and data management. It processes extensive media
https://github.com/DenisSerniuk libraries to detect duplicates, similar assets, and low-value content using ef cient
analysis algorithms. The app is designed to handle thousands of photos and
videos with minimal memory footprint and fast response times. It leverages native
EDUCATION iOS frameworks such as PhotoKit and Contacts to ensure reliable and secure
Kharkiv National University of data access. A key focus was placed on performance optimization, smooth UX,
Education RadioElectronics and scalable architecture to support continuous feature growth. The product
Computer engineering introduces automation into traditionally manual work ows, signi cantly reducing
department. Master's degree in user effort. Overall, Cleanup Pro delivers a fast, scalable, and user-centric
Specialized Computer Systems solution for device storage management.For onboarding, Lottie animations were
used to create an engaging and visually appealing rst-time user experience.
lANGUAGES
Key Bene ts / Impact
• Ukrainian
• Russian • Processes large datasets (thousands of media les) with optimized
• English B2 performance
• Reduces user time spent on cleanup through AI-driven automation
TECHNICAL • Improves app responsiveness via memory and concurrency optimizations
SKILLS • Scales ef ciently (MVVM / Coordinator)
• Enhances user retention through fast and intuitive UX ows
• Programming languages: • Minimizes risk of data loss with safe and controlled cleanup logic
• Enables continuous product evolution with a exible and maintainable
Objective-c, Swift (SwiftUI), codebase
Monkey-c • Uses Core Data
• Development tools: Xcode,
Technologies: MVVM + Coordinator, Vision SDK, Core Data, async/await, SwiftUI,
SourceTree, VC Studio, PDM, Autolayout, Crashlitics, AppHud, AppsFlyer, Firebase, Ads, GCD, Photos,
GitHub Desktop Lottie, Figma, Jira
• Version control systems: SVN,
GIT, BitBucket Digisgroup aug 2025
• Bug tracking: Redmine, Jira, Senior iOs developer
Trello Taxi application
• CI/CD: Jenkins, Fastline, Taxi calling application that works in the US and UK markets.
CircleCi Key Responsibilities:
• As a developer implement new design to existing application
TECHNOLOGIES • Support and xed bugs related with legacy code.
• Update old third party library.
MapKit, CoreLocation, Facebook SDK, • Developed new features based on business requirements.
Google API, QuartzCore, PayPal SDK • Implement new sign in and sign up ow. Implement Apple Sign In
CFNetworking, CoreAnimation, Technologies: MVC and MVVM, Codable, Async/Await, AFNetworking,
Alamo re, GCD, Operation, KVC, Accessibility Testing, CallKit, Firebase, PDM, Autolayout, Alamo re, Crashlitics,
KVO, Pods, Crashlytics, Fabric, Con uence, Apple Sing In.
CoreData, SQLLite, Twitter API
HTTP, HTTPS, Sockets, iAd, Dropbox
API, Firebase, Braintree, standard
CoreBluetooth, CallKit, Keycloak
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 Realm, PushNoti cation, Facebook SDK, Ingenio 2024 - 2025
AdSupport, Apps yer, Local Noti cation, Senior iOs developer
MVVM, MVP, VIPER, RXSwift, Texture,
AFSpeechRecognizer, KeyChain, Multi-brand product for providing advisory services.
Con uence, SOLID, StoreKit, HIG, KISS, Application for nding advisors, providing a unique, friendly, and supportive
AppHud, async/await, URLSession, environment. With options for all interests and budgets, and the ability to stay in
R.swift, Cartography touch even after a session, via chat with advisor. Application more than 10 year in
appstore.
Key Responsibilities:
• Collaborated with an international team to develop a multi-brand application
for video and voice calls, tailored for users across di erent countries.
• Designed and implemented a new logging system with JWT token support and
server-side synchronization.
• Developed new features based on business requirements.
• Maintained and improved legacy code to ensure application stability and
performance.
• Support migration of the old application to the new one
Technologies: VIPER, Codable, Async/Avait, URLSession, UnitTest, Accessibility
Testing, CallKit, Firebase, Pods, PDM, Fastline, Factory, Autolayout, Alamo re,
Crashlitics, Mixpanel, Con uence

Appstore: https://apps.apple.com/ua/app/kasamba-advisors/id6476620553
https://apps.apple.com/ua/app/purple-ocean-psychic-reading/id926748329

MDA 2019 - 2024
iOS developer
Medical application for treating user health data. Added full logic connection with
server side. New functionality included:
- data migration.
- implement new UI
- create user authentication ow (Login, Sign In, Forgot Password),
- implement multipart request for data sync, update and upload user avatar
- implement login via Keycloak service
- implement sync reminder data
- implement custom image loader service with caching user avatar and update it
by time period
- x bugs with bluetooth connection between app and sensor

Technologies: MVVM + Coordinator, Pods, Swift Package manager, Alamo re,
HTTPS, NSCache, Realm, Cartography, R.swift, Combine, Firebase, Keyckloak,
Puth Noti cation, Local Noti cation, Calendar, Multipart request, Image Loader,
CI/CD, Test Accessibility

Appstore: https://apps.apple.com/ua/app/masimo-radius-t/id1537213321

Social Networking Application.
Application has several roles, user, responder, company. User select or can
search responder and record video to user. After record video send to responder.
Responder - see list of question and can select one or more video and answer to
question, after responder answer to question he can customise foreground and
background to promote some brand or list of brands. Responder can create own
background or foreground.

Technologies: MVVM + Coordinator + Combine, Swift Package manager,
Alamo re, HTTPS, Firebase, Puth Noti cation, Calendar, AVCaptureSession,
AFSpeechRecognizer, SnapKit, KeyChain

Appstore: https://apps.apple.com/ua/app/pressr/id1017959618

Garmin Watch application.
Application for tracking activity via custom sensor.
The application displays data from the sensor such as respiratory rate, hear rate,
speed, distance ets. App has ability to customise data like show data on screen
or measurement system. Also user can connect sensor from the application, also
save sensor for quick connection on the next time you start the application.
Technologies: Monkey-c, Garmin toolkit documentation.
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 Health care application.
Medical application created for Hospital. Before using the application, the user
receives a personal ID from the doctor to continue working with the application.
Next, he goes through the registration process, sets his body parameters,
connects the application to his Garmin account. In the application, the user
tracks his training progress, chooses a training course, and the user can connect
a belt to the cardio training to track pulse in real time. Application provide two
way sync process like getting old data from backend, load training videos,
sending user data after training.
Technologies: MVVM+Combine, Multipart Request, Alamo re, CoreBluetooth,
Coordinator, MKWebKit, Codable, MapKit, CoreLocation, Postman
Health care application (iOs + Garmin).
Application for analysing user body measurements. Application search and
connect to Garmin watch after connection was successful, getting all available
data about user activity like:
- heart rate
- Motion Intensity
- Move IQ Event
- Stress data, ets.
All available date store on device or can be sync with server, via sending le.
Technologies: MVVM-Coodinator, Alamo re, KeyChain, GarminHealsSDK,
Autolayout

Quadecco GBH 2011 - 2019

iOS developer

Location-Based Photo Assistance application
The main idea of the application is requesting other users that are located
at places you are interested in for some information

Management App for sport clubs
This is an iPhone application meant for sport clubs and their members to
manage fun and effective work process including

IOT project – the application to manage temperature at home or o ce
This is a mobile application created for the company that provides smart
heating solutions.

Coupons/offers application (2014). The application is meant both for the
buyers and the sellers (shop owners).

E-shop allows the user to design by himself/herself and buy
the jewelry of his/her dream online. The user may select the
type of the product (ring, necklace, earrings, etc.), its style, kind of metal, size (or
length), the desirable diamond or gemstone for it with the help of provided lters.
He can use lters in any order he/she wishes (for example, at rst to select the
style andthen the kind of metal, diamonds or gemstones, etc., or in another order
— at rst to select diamonds or gemstones and then select for them an
appropriate shape, kind of metal, etc.). Provided lters allow the user to search for
a concrete diamond and ndmatching settings to it. Each setting adheres to
Provided lters allow the user to search for a concrete diamond and ndmatching
settings to it. Each setting adheres to particular shapes and carat sizes.
After all necessary lters are completed, the user can review the nal combination
and the price for it. If the result suits the user, he/she can add it to the cart and
order. The user can send an e-mail to the manufacturer with questions or
clari cations, if it is necessary. There is also the mobile version of jewelry e-shop
for iOS and Android platforms to help users to get the desirable product by a
preferred way

App for storaging restaurant checks
A user can download and storage his checks via NFC tag or QR code. If he
doesn’t have the App installed on his iPhone yet he will be rst directed to the
website where he can see the link to App on Appstore after reading the NFC tag.
After downloading the App he
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will see his check saved there. If he has the App installed his checks will
automatically saved in the app after reading NFC tag or